On Mon, Mar 21, 2016 at 12:08:27PM -0500, Andreas Dannenberg wrote: > +static int tas5720_set_dai_sysclk(struct snd_soc_dai *dai, int clk_id, > + unsigned int freq, int dir) > +{ > + /* > + * Nothing to configure here for TAS5720. It's a simple codec slave. > + * However we need to keep this function in here otherwise the ASoC > + * platform driver will throw an ENOTSUPP at us when trying to play > + * audio. > + */ > + > + return 0; > +} Remove empty funnctions, -ENOTSUPP is expected behaviour for anything that isn't explicitly supported by a driver. > + if (unlikely(!tx_mask)) { unlikely() is for optimising hot paths, just write the logic clearly unless there's a reason for it. > +static irqreturn_t tas5720_irq_handler(int irq, void *_dev) > +{ > + /* > + * Immediately disable TAS5720 FAULTZ interrupts inside the low-level > + * handler to prevent the system getting saturated or even overrun > + * by interrupt requests. Normally the fact that we create a threaded > + * interrupt with IRQF_ONESHOT should take care of this as by design > + * it masks interrupts while the thread is processed however testing > + * has shown that at the high frequency the FAULTZ signal triggers > + * (every 300us!) occasionally the system would lock up even with a > + * threaded handler that's completely empty until the Kernel breaks the > + * cycle, disables that interrupt, and reports a "nobody cared" error. > + * > + * Disabling the interrupt here combined with a deferred re-enabling > + * after the thread has run not only prevents this lock condition but > + * also helps to rate-limit the processing of FAULTZ interrupts. > + */ > + disable_irq_nosync(irq); No, this is completely broken. Whatever is going on in your system with the interrupt core you need to address that at the appropriate level not by putting a nonsensical bodge in here. The interrupt is disabled while the threaded handler is running, if that's not having the desired effect then whatever causes that needs to be fixed. > +static int tas5720_dapm_post_event(struct snd_soc_dapm_widget *w, > + struct snd_kcontrol *kcontrol, int event) > +{ > + struct snd_soc_codec *codec = snd_soc_dapm_to_codec(w->dapm); > + int ret; > + > + switch (event) { > + case SND_SOC_DAPM_POST_PMU: > + /* > + * Check if the codec is still powered up in which case exit > + * right away also skipping the shutdown-to-active wait time. > + */ > + ret = snd_soc_test_bits(codec, TAS5720_POWER_CTRL_REG, > + TAS5720_SDZ, 0); I don't understand this. Why on earth would we be calling the PMU handler if the widget was not previously powered? > + /* > + * Take TAS5720 out of shutdown mode in preparation for widget > + * power up. > + */ > + ret = snd_soc_update_bits(codec, TAS5720_POWER_CTRL_REG, > + TAS5720_SDZ, TAS5720_SDZ); > + if (ret < 0) { > + dev_err(codec->dev, "error waking codec: %d\n", ret); > + return ret; > + } This is a _POST_PMU handler not a pre-PMU handler... > + /* Events used to control the TAS5720 SHUTDOWN state */ > + SND_SOC_DAPM_PRE("Pre Event", tas5720_dapm_pre_event), > + SND_SOC_DAPM_POST("Post Event", tas5720_dapm_post_event), Oh, we're using _PRE() and _POST() events... this almost certainly indicates a problem, there are very few circumstances where these are a good idea and I'm not seeing anything in this driver which indicates that this is going on. Please just use normal DAPM widgets (I'm guessing a PGA) to represent the device and work within DAPM, don't shoehorn some bodge around the side.
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